Instant messaging (IM) systems are used to send messages between users over a network (e.g., the Internet or an intranet) in real-time. Once delivered, the messages typically remain on a receiving user's system until processed by the receiving user. Such static persistence of received messages is not always desirable for reasons of security. In addition, although most IM clients automatically display messages for viewing, there may be times when a receiving user would like to make sure that no one else can view the messages. Again, this feature of IM systems raises security concerns.
Currently, IM users can only handle sensitive messages indirectly. That is, they must manually anticipate their environment and change the properties of their IM client to accommodate their current environment. For example, a user might find himself in a meeting sitting next to several co-workers, clients, or even competitors. In this type of situation, the user may wish to have a private IM conversation to which those around him are not privy. To protect that privacy, the user can move his laptop or computing device to a position where it cannot be seen by those close to him. This is often disruptive to a meeting and may promote an attitude of distrust between co-workers, clients, and associates. It is also not reliable. Another option is to simply turn off IM availability so that a user cannot receive any messages. This is less then ideal since IM messages can be of a mission critical nature or offer a competitive edge to the user. Another possible solution is to configure the IM client such that it does not bring new IM windows to the foreground, and then purposefully place another application window in the foreground so that the content of the IM window cannot be seen. This process can be cumbersome, especially during long IM sessions, because the user must constantly alternate between windows when reading/composing and hiding IM messages. Another known solution consists of constantly closing the IM window so that the previous content of that window is no longer visible on the display. This does not prevent those within viewing distance from reading the content in real-time, but it does help to a degree. One disadvantage with this technique is that the user cannot see a history of the conversation or easily store that conversation in its entirety.